U.S. patent application number 12/865019 was filed with the patent office on 2014-03-20 for method and device for producing slabstock foam.
This patent application is currently assigned to Bayer MaterialScience AG. The applicant listed for this patent is Jutta Huland. Invention is credited to Sascha Fahlenkamp, Klaus-Werner Huland, Erwin Otto, Roger Scholz, Joachim Tykfer.
Application Number | 20140077407 12/865019 |
Document ID | / |
Family ID | 40577361 |
Filed Date | 2014-03-20 |
United States Patent
Application |
20140077407 |
Kind Code |
A1 |
Huland; Klaus-Werner ; et
al. |
March 20, 2014 |
METHOD AND DEVICE FOR PRODUCING SLABSTOCK FOAM
Abstract
The present invention concerns a method for the production of
slabstock foam, wherein a vessel which is open on its underside is
placed onto the bottom of a foaming box, the vessel is filled with
reaction components and subsequently removed. In the utilized
vessel its horizontal cross-sectional contour can be described by,
starting from a basic body which comprises at least three corners,
a protrusion (3) is provided in the area of at least one of the
corners. The invention further concerns a device for the
discontinuous production of slabstock foam, comprising a foaming
box and lid (11) to be placed into the foaming box. The lid (11)
comprises an opening (12) which matches the contour of a vessel
whose horizontal cross-sectional contour can be described by,
starting from a basic body which comprises at least three corners,
a protrusion (3) is provided in the area of at least one of the
corners. The vessel may be characterized as a "golden bucket".
Inventors: |
Huland; Klaus-Werner;
(Wermelskirchen, DE) ; Fahlenkamp; Sascha; (Koln,
DE) ; Tykfer; Joachim; (Leverkusen, DE) ;
Otto; Erwin; (Leverkusen, DE) ; Scholz; Roger;
(Doenrade, NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Huland; Jutta |
Wermelskirchen |
|
DE |
|
|
Assignee: |
Bayer MaterialScience AG
Leverkusen
DE
|
Family ID: |
40577361 |
Appl. No.: |
12/865019 |
Filed: |
January 29, 2009 |
PCT Filed: |
January 29, 2009 |
PCT NO: |
PCT/EP09/00554 |
371 Date: |
November 5, 2010 |
Current U.S.
Class: |
264/54 ;
249/117 |
Current CPC
Class: |
B29C 33/42 20130101;
B29C 44/025 20130101; B29C 44/586 20130101; B29C 44/38 20130101;
B29C 33/44 20130101 |
Class at
Publication: |
264/54 ;
249/117 |
International
Class: |
B29C 44/02 20060101
B29C044/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 31, 2008 |
DE |
10 2008 007 078.5 |
Claims
1.-10. (canceled)
11. A method for the production of slabstock foam, the method
comprising: placing a vessel which is open on its underside onto a
bottom of a foaming box, wherein the vessel has a horizontal
cross-sectional contour comprising at least three corners, with a
protrusion extending from at least one of the corners; filling the
vessel with reaction components; and subsequently removing the
vessel from the foaming box.
12. The method according to claim 11, wherein the horizontal
cross-sectional contour comprises four corners, with a protrusion
extending from each corner and adjacent corners being connected by
concave lines.
13. The method according to claim 11, wherein the horizontal
cross-sectional contour comprises four corners, with a protrusion
extending from each corner and adjacent corners being connected by
convex lines.
14. The method according to claim 11, wherein the horizontal
cross-sectional contour comprises four corners, with a protrusion
extending from each corner and adjacent corners being connected by
straight lines.
15. The method according to claim 14, wherein the horizontal
cross-sectional contour is based on a rectangle, with the long side
of the contour and a long side of the foaming box having a length
ratio of .gtoreq.1:2 to .ltoreq.1:5.
16. The method according to claim 14, wherein the cross-sectional
contour is based on a rectangle, with the short side of the contour
and a short side of the foaming box having a length ratio of
.gtoreq.1:2 to .ltoreq.1:5.
17. The method according to claim 14, wherein the cross-sectional
contour is based on a rectangle, the protrusions are formed by a
circular arc, and for each protrusion, a distance of a center of
the circular arc to a corresponding corner of the rectangle, on the
one hand, and a radius of the circular arc, on the other hand, have
a length ratio of .gtoreq.1:10 to .ltoreq.5.1:1.
18. The method according to claim 14, wherein the cross-sectional
contour is based on a rectangle, the protrusions are formed by a
circular arc, and for each protrusion, a radius of the circular arc
and a side of the rectangle have a length ratio of .gtoreq.1:1 to 5
.ltoreq.1:10.
19. The method according to claim 11, wherein the slabstock foam is
polyurethane foam and the reaction components comprise a polyol
component and an isocyanate component.
20. A device for the discontinuous production of slabstock foam,
the device comprising: a foaming box; and a lid adapted to be
placed into the foaming box, wherein the lid comprises an opening
having a horizontal cross-sectional contour comprising at least
three corners, with a protrusion extending from at least one of the
corners.
21. The device according to claim 20, wherein the horizontal
cross-sectional contour comprises four corners, with a protrusion
extending from each corner and adjacent corners being connected by
concave lines.
22. The device according to claim 20, wherein the horizontal
cross-sectional contour comprises four corners, with a protrusion
extending from each corner and adjacent corners are connected by
convex lines.
23. The device according to claim 20, wherein the horizontal
cross-sectional contour comprises four corners, with a protrusion
extending from each corner and adjacent corners being connected by
convex lines.
24. The device according to claim 23, wherein the horizontal
cross-sectional contour is based on a rectangle, with the long side
of the contour and a long side of the foaming box having a length
ratio of .gtoreq.1:2 to .ltoreq.1:5
25. The device according to claim 23, wherein the cross-sectional
contour is based on a rectangle, with the short side of the contour
and a short side of the foaming box having a length ratio of
.gtoreq.1:2 to .ltoreq.1:5.
26. The device according to claim 23, wherein the cross-sectional
contour is based on a rectangle, the protrusions are formed by a
circular arc, and for each protrusion, a distance of a center of
the circular arc to a corresponding corner of the rectangle, on the
one hand, and a radius of the circular arc, on the other hand, have
a length ratio of .gtoreq.1:10 to .ltoreq.1:1.
27. The device according to claim 23, wherein the cross-sectional
contour is based on a rectangle, the protrusions are formed by a
circular arc, and for each protrusion, a radius of the circular arc
and a side of the rectangle have a length ratio of .gtoreq.1:1 to
.ltoreq.1:10.
Description
[0001] The present invention concerns a method and a device for the
production of slabstock foam, wherein a vessel which is open on its
underside is placed onto the bottom of a foaming box, the vessel is
filled with foam forming reaction components and subsequently
removed.
[0002] In the discontinuous process for the production of slabstock
foam, for example for the production of polyurethane foam, usually
a reaction mixture is applied to the bottom of a container. The
reaction mixture foams, expands during the foaming and occupies the
volume provided by the container. The container is frequently
referred to as a foaming box and the process as discontinuous box
foaming.
[0003] When the reaction mixture is prepared in a mixing head
immediately prior to the production of the slabstock foam and
applied to the bottom of the container, a certain amount of time
lapses between the beginning and the end of the application. During
this time the reaction mixture already flows over the bottom of the
container and reacts under formation of foam. As a result zones of
differing ages and differing reaction progress are present in the
finished product. However, this variation of properties, for
example the variation of foam density, is undesired for the further
processing of the resulting slabstock foam.
[0004] In order to apply a more homogenous reaction mixture to the
bottom of the foaming box it has been suggested to prepare the
reaction mixture in a bottomless vessel, to mix it and to remove
this vessel. This procedure is also known as the "golden
bucket".
[0005] In this respect, DE 29 01 177 A1 discloses an apparatus for
the discontinuous production of slabstock foam, wherein a mixing
means, comprising component feed lines and a stirrer, is provided
movably in a perpendicular fashion in a bridge-like frame. As a
mixing vessel the mixing means features a bottomless cylinder
barrel which is located at a head plate and which can be positioned
on the bottom of a foam box to be placed beneath the mixing means.
In these apparatuses the bottomless cylinder barrel serving as a
mixing chamber is lowered to the bottom of the foaming box prior to
the application of the reaction components. After finishing the
mixing, the mixing means with the bottomless cylinder barrel is
lifted upwards. The mixed reaction components then flow over the
bottom of the foaming box.
[0006] U.S. Pat. No. 2,649,620 discloses a method for the
production of slabstock foam, comprising the placing of a
continuous, rigid and upright standing side wall on the bottom of a
molding pan in order to confine a relatively small area therefrom
and to thus form a mixing vessel which can be disassembled. Here
also the formed mixing vessel is filled with a reaction mixture and
subsequently removed upwards. The mixing vessel as a whole has a
cylindrical form.
[0007] In the described cylindrical forms of the mixing vessel the
reaction mixture spreads radially over the bottom of the foaming
box after the vessel has been lifted. In general, the mixing vessel
is placed in the center of the foaming box. If the foaming box
itself does not have a circular cross-section, but rather the
rectangular cross-section as common in production, the wave front
of the reaction mixture will first reach the long side of the
foaming box. This is the side with the shortest distance to the
center of the bottom. Afterwards, the wave front reaches the short
sides and lastly the corners of the foaming box. When the wave
front meets the side walls the reaction mixture can only expand
upwards. This leads to layering effects and to the compression of
the material near the sides by the foaming reaction mixture further
to the interior. Because the wave fronts of the reaction mixture
reach the sides of the foaming box at different times, ultimately
inhomogenities in the final foam body will manifest themselves.
These appear especially in the form of density variations.
[0008] Due to the viscosity of the reaction mixture, the
temperature and the foam development after the onset of the
reaction, further fluid dynamic phenomena can be observed during
the flow of the mixture. If a wave front reaches the side of the
foaming box prematurely, it is partially reflected. The reflected
waves superpose with other waves in the spreading reaction mixture.
The flow of the reaction mixture itself from the mixing vessel also
creates waves. In summary, inhomogenities in the finished foam body
may also be present due to undesired wave superpositions.
[0009] From the preceding it is apparent that there is still the
need for a method for the production of slabstock foam where lower
variations in the density of the resulting foam body are present.
The present invention therefore has the object of providing such an
improved process and a device suitable for this.
[0010] According to the invention this object is met by a method
for the production of slabstock foam, wherein a vessel which is
open on its underside is placed onto the bottom of a foaming box,
the vessel is filled with reaction components and subsequently
removed and wherein furthermore in the utilized vessel its
horizontal cross-sectional contour can be described by, starting
from a basic body which comprises at least three corners, a
protrusion is provided in the area of at least one of the corners.
By this shaping it is achieved that the fluid front with the
reaction mixture spreading after the removal of the vessel
continuously adapts to the geometry of the foaming box and thus
reaches the walls and corners of the foaming box at the same time
or with less time delay than in a conventionally shaped vessel.
This results in more homogenous product properties, especially a
more uniform density distribution, in the foam body after the end
of the foaming reaction. The vessel may also be completely or
partially open on its upper side in order to receive the reaction
mixture.
[0011] The shape of the vessel and especially the contour of the
open underside is most appropriately described by considering the
horizontal cross-section of the vessel. Hence a description of the
vessel is reduced to a description of the contour of this
cross-section. The contour then indicates the position of the
vessel wall. The contour itself may be described as a combination
or merging of a basic body with form elements representing
protrusions from the interior of the vessel.
[0012] The protrusion may, for instance, take the shape of a
circular arc, an elliptical arc or a parabolic arc. The protrusion
is provided at the corners of the basic body. This means that the
protrusion is located in the area of the corner and therefore the
corner merges into the protrusion.
[0013] In an embodiment of the method according to the invention
the basic body comprises four corners, adjacent corners are
connected by concave lines and a protrusion is provided at all of
the four corners. Therefore the basic body may be described as a
quadrangle whose sides are not straight, but rather bent towards
the interior of the quadrangle. The corners of this quadrangle then
merge into the protrusions, meaning that they are encircled by the
protrusions. The joining of the exterior contours of the deformed
quadrangle and the protrusions then results in the horizontal
cross-section of the vessel.
[0014] In another embodiment of the method according to the
invention the basic body comprises four corners, adjacent corners
are connected by convex lines and a protrusion is provided at all
of the four corners. Therefore the basic body may be described as a
quadrangle whose sides are not straight, but rather bent away from
the interior of the quadrangle. The corners of this quadrangle then
merge into the protrusions, meaning that they are encircled by the
protrusions. The joining of the exterior contours of the deformed
quadrangle and the protrusions then results in the horizontal
cross-section of the vessel.
[0015] In another embodiment of the method according to the
invention the basic body comprises four corners, adjacent corners
are connected by straight lines and a protrusion is provided at all
of the four corners. Therefore the basic body may be described as a
quadrangle whose sides are straight. Opposing sides may be parallel
and adjacent sides may be orthogonally arranged towards each other.
As a result, for example, a parallelogram, a rectangle or a square
may be obtained. The corners of this quadrangle then merge into the
protrusions, meaning that they are encircled by the protrusions.
The joining of the exterior contours of the quadrangle and the
protrusions then results in the horizontal cross-section of the
vessel.
[0016] If the basic body is a rectangle, the long side of the basic
body and the long side of the foaming box may have a length ratio
of .gtoreq.1:2 to .ltoreq.1:5. The length ratio may also be in a
range of .gtoreq.1:2.5 to .ltoreq.1:4 or of .gtoreq.1:3 to
.ltoreq.1:3.5.
[0017] If the basic body is a rectangle, furthermore the short side
of the basic body and the short side of the foaming box may have a
length ratio of .gtoreq.1:2 to .ltoreq.1:5. The length ratio may
also be in a range of .gtoreq.1:2.5 to .ltoreq.1:4 or of
.gtoreq.1:3 to .ltoreq.1:3.5.
[0018] If the basic body is a rectangle, the protrusions may be
part of a circular arc and the distance of the center of the
underlying circle to the corresponding corner of the rectangle on
the one hand and the underlying radius of the circular arc on the
other hand may have a length ratio of .gtoreq.1:10 to .ltoreq.1:1.
Ultimately, this describes the distance of the circular arc
protrusion from the corner of the rectangle which is used as an
intermediary construction clement. If the stated length ratio is,
for example; 1:10, then this means that the center of the
underlying circle is has been moved by a distance of 10% of its
radius from the corner. The range of the length ratios may also be
from .gtoreq.1:50 to .ltoreq.1:1 or from .gtoreq.1:10 to
.ltoreq.1:40.
[0019] If the basic body is a rectangle and the protrusions are
part of a circular arc, the underlying radius of the circular arc
and a side of the rectangular basic body may have a length ratio of
.gtoreq.1:1 to .ltoreq.1:10, of .gtoreq.1:2 to .ltoreq.1:8 or of
.gtoreq.1:4 to .ltoreq.1:6. This describes the proportion of the
total contour of the cross-section that the protrusion
occupies.
[0020] In a further embodiment of the method according to the
invention the slabstock foam is polyurethane foam and the reaction
components comprise a polyol component and an isocyanate component.
The reaction components may either be pre-mixed and introduced into
the vessel or the polyol component and the isocyanate component may
be provided separately into the vessel and then mixed, for example
with a stirring apparatus.
[0021] Another aspect of the present invention is a device for the
discontinuous production of slabstock foam, comprising a foaming
box and lid to be placed into the foaming box. The lid comprises an
opening which matches the contour of a vessel. The horizontal
cross-sectional contour of the vessel can be described by, starting
from a basic body which comprises at least three corners, a
protrusion is provided in the area of at least one of the corners.
According to the invention it is envisioned that the lid is
supported on the bottom of the foaming box by its sidewalls so that
a cavity is formed under the lid. This cavity may be filled with a
reaction mixture using the vessel according to the invention. The
reaction mixture spreads evenly throughout the bottom of the
foaming box, foams and then presses the lid upwards in the further
course of the foam development.
[0022] The opening in the lid, meaning in the horizontal lid
surface, is adapted for receiving a vessel which can have the
previously described geometries. The device is especially suited
for the production of polyurethane foam.
[0023] The present invention is further described with reference to
the following drawings, wherein
[0024] FIG. 1 shows the horizontal cross-sectional contour of a
vessel for the method according to the invention
[0025] FIG. 2 shows the horizontal cross-sectional contour of
another vessel for the method according to the invention
[0026] FIG. 3 shows the horizontal cross-sectional contour of
another vessel for the method according to the invention
[0027] FIG. 3a shows the geometric construction of the
cross-sectional contour of the vessel from FIG. 3
[0028] FIG. 4 shows a further variation of a cross-sectional
contour from FIG. 3
[0029] FIG. 5 shows a further variation of a cross-sectional
contour from FIG. 3
[0030] FIG. 6 shows a further variation of a cross-sectional
contour from FIG. 3
[0031] FIG. 7 shows a foaming box for the production of slabstock
foam
[0032] FIG. 8a-8c show the chronological sequence of charging a
foaming box
[0033] FIG. 1 shows the horizontal cross-sectional contour of a
vessel which is used in the method according to the invention. As a
whole the vessel has an elongate cross-sectional shape with a long
side 1 and a short side 2. At the edges of the contour there are
curved protrusions 3 which may be seen as parts of a circular arc.
In the present contour the contours of the long side 1 and the
short side 2 are both concave, meaning curved towards the interior
of the vessel.
[0034] FIG. 2 shows the horizontal cross-sectional contour of a
further vessel which is used in the method according to the
invention. As a whole the vessel has an elongate cross-sectional
shape with a long side 1 and a short side 2. At the edges of the
contour there are curved protrusions 3 which may be seen as parts
of a circular arc. In the present contour the contours of the long
side 1 and the short side 2 are both convex, meaning curved away
from the interior of the vessel.
[0035] FIG. 3 shows the horizontal cross-sectional contour of a
further vessel which is used in the method according to the
invention. As a whole the vessel has an elongate shape with a long
side 1 and a short side 2. At the edges of the contour there are
curved protrusions 3 which may be seen as parts of a circular arc.
In the present contour the contours of the long side 1 and the
short side 2 are both linear. These linear sections 1 and 2 of the
contour and hence of the vessel wall can be understood as the
remains of a rectangular basic body. If sections 1 and 2 are
extended until they intersect, the rectangular basic body is
obtained geometrically. The curved protrusions 3 may likewise be
understood as parts of a circular arc.
[0036] For better understanding, FIG. 3a shows the geometric
construction of the contour or vessel side wall shown in FIG. 3.
The rectangular basic body is formed by the wall sections 1, 2, 4
and 5. The corners are depicted by points 6. At the same time, the
corners 6 are the centers for circles formed by circular arcs 3 and
7. Upon combining the circles and the rectangular basic body the
dashed segments are removed and the cross-sectional contour
according to FIG. 3 remains.
[0037] FIG. 4 shows a further variation of a horizontal
cross-section of a vessel for a method according to the invention.
As opposed to FIG. 3, the centers of the circles which form the
circular are protrusions 3 are positioned outside the rectangular
basic body with the wall sections 1 and 2.
[0038] FIG. 5 shows a further variation of a horizontal
cross-section of a vessel for a method according to the invention.
As in FIG. 3, the centers of the circles forming the circular arc
protrusions 3 are positioned on the corners of the rectangular
basic body. However, the diameter of the circles is exactly as
large as the shorter side of the rectangle, so that the wall
section 2 of FIG. 3 cannot be seen any more.
[0039] FIG. 6 shows a further variation of a horizontal
cross-section of a vessel for a method according to the invention.
As opposed to FIG. 3 the centers of the circles which form the
circular arc protrusions 3 are positioned inside the rectangular
basic body with the wall sections 1 and 2.
[0040] FIG. 7 shows a foaming box for the production of slabstock
foam. The foaming box comprises the walls 8 and 9. The fourth side
wall, 8', which is indicated in the drawing, has been opened to the
side via joints 10. Into the foaming box the lid 11 has been
placed. The lid 11 is supported by its side walls on the bottom of
the foaming box so that a cavity is created under the lid 11. This
cavity can be charged with a foam forming reaction mixture. The lid
11 also has an opening 12 which is adapted to receive a vessel. The
horizontal cross-section of the opening and hence of the
corresponding vessel is defined by a rectangular basic body which
further features curved protrusions at the corners. It is
advantageous that the opening 12 of the lid 11 corresponds to the
form of the vessel because then a better scaling of the lid against
the reaction mixture can be achieved.
[0041] FIG. 8a-8c show schematically how the bottom of a foaming
box is charged with a reaction mixture in the method according to
the invention. The viewer's perspective is directly from above onto
the foaming box. FIG. 8a shows the initial situation. The foaming
box is defined by the long sides 8, the short sides 9 and the
bottom 13. In the center of the foaming box a vessel is positioned
which has a rectangular basic body, as defined by wall sections 1
and 2, and curved protrusions 3. The vessel is filled with a foam
forming reaction mixture 14.
[0042] In FIG. 8b the vessel, which is open on its underside, has
been removed. Accordingly the reaction mixture 14 flows over the
bottom 13 of the foaming box. Due to the shape of the vessel the
reaction mixture 14 does not spread in a radial, even way. Rather,
it starts with the original vessel shape. During the course of the
reaction mixture 14 spreading, its form corresponds more and more
to the shape of the foaming box. The propagating wave front 15 is
shown with a broken line.
[0043] FIG. 8c shows a situation further on in time after the
removal of the vessel. The reaction mixture 14 now nearly
completely covers the bottom 13 of the foaming box. It can be seen
that the distance of the wave front 15 to the long sides 8 and the
short sides 9 as well as to the corners of the foaming box only
shows slight differences. The wave front 15 will reach the walls 8,
9 and the corners of the container essentially at the same
time.
[0044] The present invention has been described as belonging to a
method for the production of slabstock foam. It is also within the
scope of the invention and its equivalents that the method with the
vessel as described according to the invention may be used wherever
it is important to distribute a fluid, especially a viscous and/or
a reacting fluid, over an area in such a way that the fluid reaches
the corresponding vertical area limitations with as little a time
difference as possible.
LIST OF REFERENCE NUMERALS
[0045] 1 Side of the cross-sectional contour [0046] 2 Side of the
cross-sectional contour [0047] 3 Protrusion [0048] 4 Linear wall
section of the cross-sectional contour [0049] 5 Linear wall section
of the cross-sectional contour [0050] 6 Corner of the rectangular
basic body [0051] 7 Circular arc [0052] 8 Side of the foaming box
[0053] 9 Side of the foaming box [0054] 10 Joint [0055] 11 Lid
[0056] 12 Opening [0057] 13 Bottom of the foaming box [0058] 14
Reaction mixture [0059] 15 Wave front
* * * * *